1N5817, 1N5818, 1N5819
NOTE 5. — THERMAL CIRCUIT MODEL
(For heat conduction through the leads)
R
qS(A)
T
A(A)
T
L(A)
T
C(A)
T
J
R
qL(A)
R
qJ(A)
R
qJ(K)
P
D
T
C(K)
T
L(K)
R
qL(K)
R
qS(K)
T
A(K)
Use of the above model permits junction to lead thermal re-
sistance for any mounting configuration to be found. For a
given total lead length, lowest values occur when one side of
the rectifier is brought as close as possible to the heatsink.
Terms in the model signify:
T
A
= Ambient Temperature
T
C
= Case Temperature
T
L
= Lead Temperature
T
J
= Junction Temperature
R
qS
= Thermal Resistance, Heatsink to Ambient
R
qL
= Thermal Resistance, Lead to Heatsink
R
qJ
= Thermal Resistance, Junction to Case
P
D
= Power Dissipation
IFSM, PEAK SURGE CURRENT (AMP)
(Subscripts A and K refer to anode and cathode sides, re-
spectively.) Values for thermal resistance components are:
R
qL
= 100°C/W/in typically and 120°C/W/in maximum
R
qJ
= 36°C/W typically and 46°C/W maximum.
30
20
T
L
= 70°C
f = 60 Hz
10
7.0
5.0
Surge Applied at
Rated Load Conditions
3.0
1.0
2.0
3.0
5.0 7.0 10
20
NUMBER OF CYCLES
30
40
70 100
1 Cycle
20
10
7.0
iF, INSTANTANEOUS FORWARD CURRENT (AMP)
5.0
3.0
2.0
25°C
T
C
= 100°C
1.0
0.7
0.5
0.3
0.2
30
20
I R, REVERSE CURRENT (mA)
15
5.0
3.0
2.0
1.0
0.5
0.3
0.2
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0 1.1
0.05
0.03
100°C
T
J
= 125°C
Figure 8. Maximum Non−Repetitive Surge Current
0.1
0.07
0.05
0.03
0.02
0.1
75°C
25°C
1N5817
1N5818
1N5819
0
4.0
8.0
12
16
20
24
28
32
36
40
v
F
, INSTANTANEOUS FORWARD VOLTAGE (VOLTS)
V
R
, REVERSE VOLTAGE (VOLTS)
Figure 7. Typical Forward Voltage
Figure 9. Typical Reverse Current
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